Intercooler for air-compressor.



C. DAY & G. E. WINDELER. iNTERcooLER Foa AIR coMPHEssoRs.

APPLXCATION FILED JUNE 13, 1912. j

Patented Oct. 17, 1916.

CHAR/.5.5 0A? CHARLES DAY AND GEORGE E. WINDELER, OF STOCKPORT, ENGLAND,ASSIGNORS TO UNITED OFFICE. I

GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

Specification of Letters Patent.

Application led June 13, 1912. Serial No. 703,391.

To all whom t may concern Be it known that we, CHARLES DAY and GEORGE E.WINDELER, subjects of the King of Great Britain, and residing atStockport, county of Cheshire, England, have invented certain new anduseful Improvements 1n Intercoolers for Air-Compressors, of which thefollowing is a specification.

The present invention relates to lntercoolers which are more speciallyintended for use in connection with multi-stage reciprocating aircompressors that supply high pressure air to the fuel injectors orpulverizers and starting valves of high co1npression internal combustionoil engines.

The object of our invention is to improve the constructionand operationof such intercoolers whereby the maximum cooling effect may be obtainedwith a structure of relatively small size, and of simple, cheap andreliable construction.

In the accompanying drawing, which illustrates one of the embodiments ofour invention, Figure 1 is a vertical longitudinal section of anintercooler; Fig. 2 is a detail sectional view ofthe high pressure coiland its inclosing casing; Fig. 3 is a perspective view of the maincasing of the intercooler showing the means for directing the air, andFig. 4 is a plan view, partly in section, of said main casing.

Referring to the drawing, 5 indicates the main cylindrical casing whichis provided with internal radial partitions that extend lengthwise anddivide the interior thereof into a plurality of chambers through whichthe air to be cooled passes in series. In the present embodiment of ourinvention four of these chambers are provided which are substantiallequal in size. The number of these chambers can be varied as desiredcare being taken not to make them too small as this would result inundue friction or opposition to the passage of air, or too large as thiswould result in a decrease in the cooling effect. The partitions arecast jointed to the cylinder wall and to each other to avoid joints andmachine work. Each of the segmental chambers thus formed contains al-plurality of thin tubes 7 which are made of some good heat-conductingmetal such as brass. The lower ends of the tubes are seated in thebottom integral wall or vbase 8 of the casing. The holes that receivethe ends of the tubes have V-shaped grooves 9 formed therein, into whichthe metal forming theptube is forced by a suitable tool. The object ofthis arrangement is to make an air-tight joint. The upper ends of thetubes are similarly arranged, except that.,

they are mounted in-a removable plate 10 instead of a iiXed part of theCasin This plate is carefully machined and tted to the casing and alsoto the ends of the partitions, to form air-tight joints, and is held bybolts as will appear later. As -the air is under relatively highpressure, suitable precautions must be taken to prevent its escape.

Referring to Fig. 3, from which the tubes have been omitted for thepurpose of illustration, heated air under considerable pressure isadmitted to the easing from the iirst stage of the air compressor by theinlet 11. This inlet opens upwardly so that the entering air strikes thetop plates 10, Fig. 1, and isdeflected downwardly as indicated by thearrows. The lower end of the partition 12 Patented oetlrr, 1916. ,l

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is provided with a rectangular opening or 4 port 13a near its lower end,through which air under pressure passes fromthe first to the secondsegmental chamber as indicated by the dotted arrows. The upper end 0fpartition 13 is cut away to form an opening or port 14, and permits airto enter the third segmental chamber. The lower end of partition 15 isprovided with a rectangular opening or port 16 shown in dotted lines,through which air enters `the fourth, and, in this case, the lastsegmental chamber. Air is discharged from the casing by the orifices orports 17 that may be connected to the same or different pipes 18,leading to the suction valve or valves of a higher stage of thecompressor. As will appear later, the cooling Water continuously flowsthrough the tubes in the chambers from the bottom to the top. As aresult of this, it will be the lower openings or ports 13 and 1li, whichcanse an abrupt turning of the all', are lo- .cated a suitable distanceabove the base or bottom plate 8. As a result of this, the particlesheavier than air are discharged and collect in what may be termedreceptacles in the bottoms of the several chambers. In order that thecollection of water and oil may be discharged from the severalreceptacles, the outer lower corners of the partitions 12, 13 and 15 arecut away as indicated at 17a. Connected with one of the receptacles is amanually-controlled blow-off cock 18, which should be momentarily openedvfrom time to time to permit the water and oil to be discharged.

It will be evident from the above description that the air passes firstin one direction, and then in the opposite, resulting in a long andsomewhat tortuous passage. The present structure therefore has the greatadvantage of being short, while, at the same time, large coolingsurfaces are presented to the air currents.

The means for circulating cooling water through the tubes 7 will now bedescribed.

To the under side of the casing is bolted a cover 19, of suitable shapeto provide a chamber 20 between it and the bottom part 8 of the casing.Extending across this chamber, and held in place by a shoulder on thecover is a baiier or distributer 21, having a plurality of suitablyspaced holes 22, through which the cooling water iows. To the under sideof the cover is bolted a itting 23,-to which pipes 24 and 25 areconnected, the pipe 24 leading from a source of water supply such as aservice main, a cooling tower, or the like, and the pipe 25 leading toanother inter-cooler or other device. The fitting is also provided witha drain cock 26 by means of which the cooling water can be drawn off.The water passes through the tubes 7 in multiple, and enters the chamber27 formed in the top cover or bonnet 28. This bonnet is securely held inplaceby bolts 29, and-these same bolts serve to clamp the tube sheet orhead 10 in place. Water leaves the chamber 27 by the outlet pipe 30,which may be connected to a cooling tower or other receptacle. Locatedwithin the chamber is a coil of pipe 31, to which high pressure air isadmitted by the pipe 32 leading from the discharge side of the highpressure stage of the air compressor. The air after being cooled passesby the pipe 33 to a storage tank from which it is supplied to thepulverizer of the engine or to the air starting valve, or both. It willbe noted that the connections to the coil 31 are carried by a door 34which is bolted to the wall of the cover or bonnet 28. The coil andopening covered by the door are of such size that the coil can beinserted and removed through said opening. This facilitates themanufacture of the apparatus and also permits the coil to be readilyremoved for inspection or repair. Our experience has demonstrated thatthe coil can advantageously be made of drawn seamless copper tubing.

The coil 31 is placed horizontally with the outlet at the bottom so thatany moisture or oil will be conveyed by the air from the coil instead ofbeing trapped therein. It will also be noted that the same water whichcools the low pressure air also cools the high pressure air. By thisarrangement the apparatus is greatly simplified and the use of manyfittings and parts avoided. By using the baile plate 21 at the bottomall of the tubes are supplied with substantially equal amounts of waterso that the circulation is active at all points and pockets or deadspaces are avoided. In other words, the maximum effect of the coolingwater is obtained.

The pressure of air in the coil 31 is relatively high, in many cases ashigh as 950 pounds per square inch. It sometimes happens that thesecoils will split open after .considerable service, due chiefly toerosion caused by the moisture carried along with the air. If theentirebonnet or cover 28 were made solid, this high pressure mightresult in bursting it. To avoid this danger, a. safety device isprovided comprising in the present instance a thin diaphragm 35 that isheld in place by a ring 36 that is securely bolted in place. Thisdiaphragm pressure of the cooling water in the chamber 27 but should letgo when the pressure becomes excessive. Practical experience hasdemonstrated that this diaphragm can advantageously be made of rubber.The casing 5 is also provided with a safety device to prevent it frombeing subjected to excessive pressure due to any cause. An ordinary popsafety valve 37 will be found to be satisfactory for this purpose.

As before stated the means for cooling both the low and high pressureair are combined in the same casing and the same cooling water acts onboth cooling means in succession. By causing the low ressure air totravel from end to end in eac segmental chamber in the main casing, themaximum cooling effect will be obtained in a structure of small size.All other parts are simple inconstruction thereby reducing the cost ofmanufacture.

In accordance with the provisions of the patentl statutes, we have setforth what we believe to represent the best embodiment of our invention;but it is to be understood that the drawing is only illustrative andthat our invention can be carried out by other means.

What we claim as new, and desire to seshould be strong enough towithstand the cure by Letters Patent of the United States 1. In a deviceof the character described,

the combination of a casing, partitions that divide the interior of thecasing into cham bers, ports in said partitions connecting the chambers,said ports being located at the upper end of one partition and at thelower end of the next, each port which is located at the lower end of apartition being spaced from the bottom thereof whereby receptacles areformed between the partitions at the lower end of the casing, means fordischarging foreign matter from said recepta cles, tubes that extendthrough the chambers, heads for supporting the tubes at their ends, acover for one end of the casing that forms a chamber', a bonnet for theother end of the casing that contains a chamber, a coil located in thechamber in the bonnet, means for supplying a cooling medium to thechamber in the cover from which it passes through said tubes to thechamber in the bonnet, and means receiving said medium from `the chamberin the bonnet.

2. In a device of the character described, the combination of a casing,partitions that divide the casing into chambers, ports in saidpartitions connecting the chambers,

said ports being located at the upper end of one partition and at thelower end of the next, each port which is located at the lower end of apartition being spaced from the l bottom thereof whereby receptacles Aare formed between the partitions at the lower end of the casing, meansfor discharging foreign matter from said receptacles, tubes thatextendthrough the chambers, means for supporting the tubes, a chambered headfor one end of the casing to which a cooling medium is admitted, a baerin the chamber for distributing said medium to the tubes, a chamberedbonnet that receives the said medium from all of the tubes, a coil inthe chamber of the bonnet that is cooled by the medium, and means forconveying the cooling medium to the chamber in the head and from thechamber in the bonnet.

3. In a device of the character described, the combination of a casing,partitions arranged at right angles to each other in said casin anddividing the interior of it into cham iers, ports in said partitionsconnecting the chambers, said ports being located nt the upper end ofone partition and at the lower end of the next, each port which islocated at the lower end of a partition being spaced from the bottomthereof whereby receptacles are formed between the partitions at thelower end of the casing, means for discharging foreign matter from saidreceptacles, tubes that extend through the chambers, heads forsupporting the tubes at their ends, a cover for one end of the casingthat forms a chamber, a bonnet for the other end of the casing thatcontains a chamber,

a coil located in the chamber in the bonnet, means for supplying acooling medium to the chamber in the cover from which it passes throughsaid tubes to the chamber in the bonnet, and means receiving said mediumfrom the chamber in the bonnet.

In witness whereof we have hereunto set our hands and seals this 23rdday of May,

1912. CHARLES DAY. GEORGE E. WINDELER.

Witnesses:-

ALEx. F. MACDONALD, JOHN D. Giu..

